1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * GHES/EDAC Linux driver
4 *
5 * Copyright (c) 2013 by Mauro Carvalho Chehab
6 *
7 * Red Hat Inc. https://www.redhat.com
8 */
9
10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12 #include <acpi/ghes.h>
13 #include <linux/edac.h>
14 #include <linux/dmi.h>
15 #include "edac_module.h"
16 #include <ras/ras_event.h>
17 #include <linux/notifier.h>
18
19 #define OTHER_DETAIL_LEN 400
20
21 struct ghes_pvt {
22 struct mem_ctl_info *mci;
23
24 /* Buffers for the error handling routine */
25 char other_detail[OTHER_DETAIL_LEN];
26 char msg[80];
27 };
28
29 static refcount_t ghes_refcount = REFCOUNT_INIT(0);
30
31 /*
32 * Access to ghes_pvt must be protected by ghes_lock. The spinlock
33 * also provides the necessary (implicit) memory barrier for the SMP
34 * case to make the pointer visible on another CPU.
35 */
36 static struct ghes_pvt *ghes_pvt;
37
38 /*
39 * This driver's representation of the system hardware, as collected
40 * from DMI.
41 */
42 static struct ghes_hw_desc {
43 int num_dimms;
44 struct dimm_info *dimms;
45 } ghes_hw;
46
47 /* GHES registration mutex */
48 static DEFINE_MUTEX(ghes_reg_mutex);
49
50 /*
51 * Sync with other, potentially concurrent callers of
52 * ghes_edac_report_mem_error(). We don't know what the
53 * "inventive" firmware would do.
54 */
55 static DEFINE_SPINLOCK(ghes_lock);
56
57 static bool system_scanned;
58
59 static struct list_head *ghes_devs;
60
61 /* Memory Device - Type 17 of SMBIOS spec */
62 struct memdev_dmi_entry {
63 u8 type;
64 u8 length;
65 u16 handle;
66 u16 phys_mem_array_handle;
67 u16 mem_err_info_handle;
68 u16 total_width;
69 u16 data_width;
70 u16 size;
71 u8 form_factor;
72 u8 device_set;
73 u8 device_locator;
74 u8 bank_locator;
75 u8 memory_type;
76 u16 type_detail;
77 u16 speed;
78 u8 manufacturer;
79 u8 serial_number;
80 u8 asset_tag;
81 u8 part_number;
82 u8 attributes;
83 u32 extended_size;
84 u16 conf_mem_clk_speed;
85 } __attribute__((__packed__));
86
find_dimm_by_handle(struct mem_ctl_info * mci,u16 handle)87 static struct dimm_info *find_dimm_by_handle(struct mem_ctl_info *mci, u16 handle)
88 {
89 struct dimm_info *dimm;
90
91 mci_for_each_dimm(mci, dimm) {
92 if (dimm->smbios_handle == handle)
93 return dimm;
94 }
95
96 return NULL;
97 }
98
dimm_setup_label(struct dimm_info * dimm,u16 handle)99 static void dimm_setup_label(struct dimm_info *dimm, u16 handle)
100 {
101 const char *bank = NULL, *device = NULL;
102
103 dmi_memdev_name(handle, &bank, &device);
104
105 /*
106 * Set to a NULL string when both bank and device are zero. In this case,
107 * the label assigned by default will be preserved.
108 */
109 snprintf(dimm->label, sizeof(dimm->label), "%s%s%s",
110 (bank && *bank) ? bank : "",
111 (bank && *bank && device && *device) ? " " : "",
112 (device && *device) ? device : "");
113 }
114
assign_dmi_dimm_info(struct dimm_info * dimm,struct memdev_dmi_entry * entry)115 static void assign_dmi_dimm_info(struct dimm_info *dimm, struct memdev_dmi_entry *entry)
116 {
117 u16 rdr_mask = BIT(7) | BIT(13);
118
119 if (entry->size == 0xffff) {
120 pr_info("Can't get DIMM%i size\n", dimm->idx);
121 dimm->nr_pages = MiB_TO_PAGES(32);/* Unknown */
122 } else if (entry->size == 0x7fff) {
123 dimm->nr_pages = MiB_TO_PAGES(entry->extended_size);
124 } else {
125 if (entry->size & BIT(15))
126 dimm->nr_pages = MiB_TO_PAGES((entry->size & 0x7fff) << 10);
127 else
128 dimm->nr_pages = MiB_TO_PAGES(entry->size);
129 }
130
131 switch (entry->memory_type) {
132 case 0x12:
133 if (entry->type_detail & BIT(13))
134 dimm->mtype = MEM_RDDR;
135 else
136 dimm->mtype = MEM_DDR;
137 break;
138 case 0x13:
139 if (entry->type_detail & BIT(13))
140 dimm->mtype = MEM_RDDR2;
141 else
142 dimm->mtype = MEM_DDR2;
143 break;
144 case 0x14:
145 dimm->mtype = MEM_FB_DDR2;
146 break;
147 case 0x18:
148 if (entry->type_detail & BIT(12))
149 dimm->mtype = MEM_NVDIMM;
150 else if (entry->type_detail & BIT(13))
151 dimm->mtype = MEM_RDDR3;
152 else
153 dimm->mtype = MEM_DDR3;
154 break;
155 case 0x1a:
156 if (entry->type_detail & BIT(12))
157 dimm->mtype = MEM_NVDIMM;
158 else if (entry->type_detail & BIT(13))
159 dimm->mtype = MEM_RDDR4;
160 else
161 dimm->mtype = MEM_DDR4;
162 break;
163 default:
164 if (entry->type_detail & BIT(6))
165 dimm->mtype = MEM_RMBS;
166 else if ((entry->type_detail & rdr_mask) == rdr_mask)
167 dimm->mtype = MEM_RDR;
168 else if (entry->type_detail & BIT(7))
169 dimm->mtype = MEM_SDR;
170 else if (entry->type_detail & BIT(9))
171 dimm->mtype = MEM_EDO;
172 else
173 dimm->mtype = MEM_UNKNOWN;
174 }
175
176 /*
177 * Actually, we can only detect if the memory has bits for
178 * checksum or not
179 */
180 if (entry->total_width == entry->data_width)
181 dimm->edac_mode = EDAC_NONE;
182 else
183 dimm->edac_mode = EDAC_SECDED;
184
185 dimm->dtype = DEV_UNKNOWN;
186 dimm->grain = 128; /* Likely, worse case */
187
188 dimm_setup_label(dimm, entry->handle);
189
190 if (dimm->nr_pages) {
191 edac_dbg(1, "DIMM%i: %s size = %d MB%s\n",
192 dimm->idx, edac_mem_types[dimm->mtype],
193 PAGES_TO_MiB(dimm->nr_pages),
194 (dimm->edac_mode != EDAC_NONE) ? "(ECC)" : "");
195 edac_dbg(2, "\ttype %d, detail 0x%02x, width %d(total %d)\n",
196 entry->memory_type, entry->type_detail,
197 entry->total_width, entry->data_width);
198 }
199
200 dimm->smbios_handle = entry->handle;
201 }
202
enumerate_dimms(const struct dmi_header * dh,void * arg)203 static void enumerate_dimms(const struct dmi_header *dh, void *arg)
204 {
205 struct memdev_dmi_entry *entry = (struct memdev_dmi_entry *)dh;
206 struct ghes_hw_desc *hw = (struct ghes_hw_desc *)arg;
207 struct dimm_info *d;
208
209 if (dh->type != DMI_ENTRY_MEM_DEVICE)
210 return;
211
212 /* Enlarge the array with additional 16 */
213 if (!hw->num_dimms || !(hw->num_dimms % 16)) {
214 struct dimm_info *new;
215
216 new = krealloc_array(hw->dimms, hw->num_dimms + 16,
217 sizeof(struct dimm_info), GFP_KERNEL);
218 if (!new) {
219 WARN_ON_ONCE(1);
220 return;
221 }
222
223 hw->dimms = new;
224 }
225
226 d = &hw->dimms[hw->num_dimms];
227 d->idx = hw->num_dimms;
228
229 assign_dmi_dimm_info(d, entry);
230
231 hw->num_dimms++;
232 }
233
ghes_scan_system(void)234 static void ghes_scan_system(void)
235 {
236 if (system_scanned)
237 return;
238
239 dmi_walk(enumerate_dimms, &ghes_hw);
240
241 system_scanned = true;
242 }
243
print_mem_error_other_detail(const struct cper_sec_mem_err * mem,char * msg,const char * location,unsigned int len)244 static int print_mem_error_other_detail(const struct cper_sec_mem_err *mem, char *msg,
245 const char *location, unsigned int len)
246 {
247 u32 n;
248
249 if (!msg)
250 return 0;
251
252 n = 0;
253 len -= 1;
254
255 n += scnprintf(msg + n, len - n, "APEI location: %s ", location);
256
257 if (!(mem->validation_bits & CPER_MEM_VALID_ERROR_STATUS))
258 goto out;
259
260 n += scnprintf(msg + n, len - n, "status(0x%016llx): ", mem->error_status);
261 n += scnprintf(msg + n, len - n, "%s ", cper_mem_err_status_str(mem->error_status));
262
263 out:
264 msg[n] = '\0';
265
266 return n;
267 }
268
ghes_edac_report_mem_error(struct notifier_block * nb,unsigned long val,void * data)269 static int ghes_edac_report_mem_error(struct notifier_block *nb,
270 unsigned long val, void *data)
271 {
272 struct cper_sec_mem_err *mem_err = (struct cper_sec_mem_err *)data;
273 struct cper_mem_err_compact cmem;
274 struct edac_raw_error_desc *e;
275 struct mem_ctl_info *mci;
276 unsigned long sev = val;
277 struct ghes_pvt *pvt;
278 unsigned long flags;
279 char *p;
280
281 /*
282 * We can do the locking below because GHES defers error processing
283 * from NMI to IRQ context. Whenever that changes, we'd at least
284 * know.
285 */
286 if (WARN_ON_ONCE(in_nmi()))
287 return NOTIFY_OK;
288
289 spin_lock_irqsave(&ghes_lock, flags);
290
291 pvt = ghes_pvt;
292 if (!pvt)
293 goto unlock;
294
295 mci = pvt->mci;
296 e = &mci->error_desc;
297
298 /* Cleans the error report buffer */
299 memset(e, 0, sizeof (*e));
300 e->error_count = 1;
301 e->grain = 1;
302 e->msg = pvt->msg;
303 e->other_detail = pvt->other_detail;
304 e->top_layer = -1;
305 e->mid_layer = -1;
306 e->low_layer = -1;
307 *pvt->other_detail = '\0';
308 *pvt->msg = '\0';
309
310 switch (sev) {
311 case GHES_SEV_CORRECTED:
312 e->type = HW_EVENT_ERR_CORRECTED;
313 break;
314 case GHES_SEV_RECOVERABLE:
315 e->type = HW_EVENT_ERR_UNCORRECTED;
316 break;
317 case GHES_SEV_PANIC:
318 e->type = HW_EVENT_ERR_FATAL;
319 break;
320 default:
321 case GHES_SEV_NO:
322 e->type = HW_EVENT_ERR_INFO;
323 }
324
325 edac_dbg(1, "error validation_bits: 0x%08llx\n",
326 (long long)mem_err->validation_bits);
327
328 /* Error type, mapped on e->msg */
329 if (mem_err->validation_bits & CPER_MEM_VALID_ERROR_TYPE) {
330 u8 etype = mem_err->error_type;
331
332 p = pvt->msg;
333 p += snprintf(p, sizeof(pvt->msg), "%s", cper_mem_err_type_str(etype));
334 } else {
335 strcpy(pvt->msg, "unknown error");
336 }
337
338 /* Error address */
339 if (mem_err->validation_bits & CPER_MEM_VALID_PA) {
340 e->page_frame_number = PHYS_PFN(mem_err->physical_addr);
341 e->offset_in_page = offset_in_page(mem_err->physical_addr);
342 }
343
344 /* Error grain */
345 if (mem_err->validation_bits & CPER_MEM_VALID_PA_MASK)
346 e->grain = ~mem_err->physical_addr_mask + 1;
347
348 /* Memory error location, mapped on e->location */
349 p = e->location;
350 cper_mem_err_pack(mem_err, &cmem);
351 p += cper_mem_err_location(&cmem, p);
352
353 if (mem_err->validation_bits & CPER_MEM_VALID_MODULE_HANDLE) {
354 struct dimm_info *dimm;
355
356 p += cper_dimm_err_location(&cmem, p);
357 dimm = find_dimm_by_handle(mci, mem_err->mem_dev_handle);
358 if (dimm) {
359 e->top_layer = dimm->idx;
360 strcpy(e->label, dimm->label);
361 }
362 }
363 if (p > e->location)
364 *(p - 1) = '\0';
365
366 if (!*e->label)
367 strcpy(e->label, "unknown memory");
368
369 /* All other fields are mapped on e->other_detail */
370 p = pvt->other_detail;
371 p += print_mem_error_other_detail(mem_err, p, e->location, OTHER_DETAIL_LEN);
372 if (p > pvt->other_detail)
373 *(p - 1) = '\0';
374
375 edac_raw_mc_handle_error(e);
376
377 unlock:
378 spin_unlock_irqrestore(&ghes_lock, flags);
379
380 return NOTIFY_OK;
381 }
382
383 static struct notifier_block ghes_edac_mem_err_nb = {
384 .notifier_call = ghes_edac_report_mem_error,
385 .priority = 0,
386 };
387
ghes_edac_register(struct device * dev)388 static int ghes_edac_register(struct device *dev)
389 {
390 bool fake = false;
391 struct mem_ctl_info *mci;
392 struct ghes_pvt *pvt;
393 struct edac_mc_layer layers[1];
394 unsigned long flags;
395 int rc = 0;
396
397 /* finish another registration/unregistration instance first */
398 mutex_lock(&ghes_reg_mutex);
399
400 /*
401 * We have only one logical memory controller to which all DIMMs belong.
402 */
403 if (refcount_inc_not_zero(&ghes_refcount))
404 goto unlock;
405
406 ghes_scan_system();
407
408 /* Check if we've got a bogus BIOS */
409 if (!ghes_hw.num_dimms) {
410 fake = true;
411 ghes_hw.num_dimms = 1;
412 }
413
414 layers[0].type = EDAC_MC_LAYER_ALL_MEM;
415 layers[0].size = ghes_hw.num_dimms;
416 layers[0].is_virt_csrow = true;
417
418 mci = edac_mc_alloc(0, ARRAY_SIZE(layers), layers, sizeof(struct ghes_pvt));
419 if (!mci) {
420 pr_info("Can't allocate memory for EDAC data\n");
421 rc = -ENOMEM;
422 goto unlock;
423 }
424
425 pvt = mci->pvt_info;
426 pvt->mci = mci;
427
428 mci->pdev = dev;
429 mci->mtype_cap = MEM_FLAG_EMPTY;
430 mci->edac_ctl_cap = EDAC_FLAG_NONE;
431 mci->edac_cap = EDAC_FLAG_NONE;
432 mci->mod_name = "ghes_edac.c";
433 mci->ctl_name = "ghes_edac";
434 mci->dev_name = "ghes";
435
436 if (fake) {
437 pr_info("This system has a very crappy BIOS: It doesn't even list the DIMMS.\n");
438 pr_info("Its SMBIOS info is wrong. It is doubtful that the error report would\n");
439 pr_info("work on such system. Use this driver with caution\n");
440 }
441
442 pr_info("This system has %d DIMM sockets.\n", ghes_hw.num_dimms);
443
444 if (!fake) {
445 struct dimm_info *src, *dst;
446 int i = 0;
447
448 mci_for_each_dimm(mci, dst) {
449 src = &ghes_hw.dimms[i];
450
451 dst->idx = src->idx;
452 dst->smbios_handle = src->smbios_handle;
453 dst->nr_pages = src->nr_pages;
454 dst->mtype = src->mtype;
455 dst->edac_mode = src->edac_mode;
456 dst->dtype = src->dtype;
457 dst->grain = src->grain;
458
459 /*
460 * If no src->label, preserve default label assigned
461 * from EDAC core.
462 */
463 if (strlen(src->label))
464 memcpy(dst->label, src->label, sizeof(src->label));
465
466 i++;
467 }
468
469 } else {
470 struct dimm_info *dimm = edac_get_dimm(mci, 0, 0, 0);
471
472 dimm->nr_pages = 1;
473 dimm->grain = 128;
474 dimm->mtype = MEM_UNKNOWN;
475 dimm->dtype = DEV_UNKNOWN;
476 dimm->edac_mode = EDAC_SECDED;
477 }
478
479 rc = edac_mc_add_mc(mci);
480 if (rc < 0) {
481 pr_info("Can't register with the EDAC core\n");
482 edac_mc_free(mci);
483 rc = -ENODEV;
484 goto unlock;
485 }
486
487 spin_lock_irqsave(&ghes_lock, flags);
488 ghes_pvt = pvt;
489 spin_unlock_irqrestore(&ghes_lock, flags);
490
491 ghes_register_report_chain(&ghes_edac_mem_err_nb);
492
493 /* only set on success */
494 refcount_set(&ghes_refcount, 1);
495
496 unlock:
497
498 /* Not needed anymore */
499 kfree(ghes_hw.dimms);
500 ghes_hw.dimms = NULL;
501
502 mutex_unlock(&ghes_reg_mutex);
503
504 return rc;
505 }
506
ghes_edac_unregister(struct ghes * ghes)507 static void ghes_edac_unregister(struct ghes *ghes)
508 {
509 struct mem_ctl_info *mci;
510 unsigned long flags;
511
512 mutex_lock(&ghes_reg_mutex);
513
514 system_scanned = false;
515 memset(&ghes_hw, 0, sizeof(struct ghes_hw_desc));
516
517 if (!refcount_dec_and_test(&ghes_refcount))
518 goto unlock;
519
520 /*
521 * Wait for the irq handler being finished.
522 */
523 spin_lock_irqsave(&ghes_lock, flags);
524 mci = ghes_pvt ? ghes_pvt->mci : NULL;
525 ghes_pvt = NULL;
526 spin_unlock_irqrestore(&ghes_lock, flags);
527
528 if (!mci)
529 goto unlock;
530
531 mci = edac_mc_del_mc(mci->pdev);
532 if (mci)
533 edac_mc_free(mci);
534
535 ghes_unregister_report_chain(&ghes_edac_mem_err_nb);
536
537 unlock:
538 mutex_unlock(&ghes_reg_mutex);
539 }
540
ghes_edac_init(void)541 static int __init ghes_edac_init(void)
542 {
543 struct ghes *g, *g_tmp;
544
545 ghes_devs = ghes_get_devices();
546 if (!ghes_devs)
547 return -ENODEV;
548
549 if (list_empty(ghes_devs)) {
550 pr_info("GHES probing device list is empty\n");
551 return -ENODEV;
552 }
553
554 list_for_each_entry_safe(g, g_tmp, ghes_devs, elist) {
555 ghes_edac_register(g->dev);
556 }
557
558 return 0;
559 }
560 module_init(ghes_edac_init);
561
ghes_edac_exit(void)562 static void __exit ghes_edac_exit(void)
563 {
564 struct ghes *g, *g_tmp;
565
566 list_for_each_entry_safe(g, g_tmp, ghes_devs, elist) {
567 ghes_edac_unregister(g);
568 }
569 }
570 module_exit(ghes_edac_exit);
571
572 MODULE_LICENSE("GPL");
573 MODULE_DESCRIPTION("Output ACPI APEI/GHES BIOS detected errors via EDAC");
574